Bump eslint-plugin-jsx-a11y from 6.7.1 to 6.8.0 in /frontend

Bumps [eslint-plugin-jsx-a11y](https://github.com/jsx-eslint/eslint-plugin-jsx-a11y) from 6.7.1 to 6.8.0.
- [Release notes](https://github.com/jsx-eslint/eslint-plugin-jsx-a11y/releases)
- [Changelog](https://github.com/jsx-eslint/eslint-plugin-jsx-a11y/blob/main/CHANGELOG.md)
- [Commits](jsx-eslint/eslint-plugin-jsx-a11y@v6.7.1...v6.8.0)

---
updated-dependencies:
- dependency-name: eslint-plugin-jsx-a11y
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>